KR20100102380A - Organic light emitting display apparatus - Google Patents

Abstract

PURPOSE: An organic light emitting display device is provided to prevent damage to a color filter layer by interposing a protection layer between a color filter layer and a black matrix when the black matrix is patterned. CONSTITUTION: A display unit(120) is formed on a substrate and includes an organic light emitting device. An encapsulation layer(130) is formed on the display unit to encapsulate the display unit. A color filter layer(140) is formed on the encapsulating layer. A protection layer(150) is formed on the color filter layer. The protection layer includes an inorganic material. A black matrix(160) is formed on the protection layer. The cover layer is formed on the black matrix.

Description

Organic light emitting display apparatus

 The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device capable of improving process efficiency and improving contrast.

Recently, display devices have been replaced by portable thin flat display devices. Among the flat panel display devices, the electroluminescent display device is a self-luminous display device, and has attracted attention as a next generation display device because of its advantages of having a wide viewing angle, excellent contrast, and fast response speed. In addition, an organic light emitting display device in which a light emitting layer is formed of an organic material has advantages in that luminance, driving voltage, and response speed are excellent and multicoloring is possible, compared to an inorganic light emitting display device.

The organic light emitting display device forms an organic light emitting layer that emits colors such as red, green, and blue in order to implement natural visible light. However, in this case, the organic light emitting layer corresponding to each of red, green, and blue has different lifetime characteristics, and thus, it is difficult to maintain white balance when driving for a long time.

In order to solve this problem, an organic light emitting layer that emits light of a single color is formed, and a color filter layer for extracting light corresponding to a predetermined color from light emitted from the organic light emitting layer or light emitted from the organic light emitting layer is converted into light of a predetermined color. There is a method of forming a color conversion layer.

In order to improve the contrast of the organic light emitting diode display, a black matrix BM may be formed of a material that absorbs visible light.

An organic light emitting diode display including both a color filter layer and a black matrix may be formed to facilitate contrast enhancement and maintain white balance. However, since the color filter layer and the black matrix require a predetermined patterning, manufacturing of the organic light emitting display device including the color filter layer and the black matrix together is not easy, thereby reducing manufacturing efficiency. Therefore, there is a limit in improving the characteristics of the organic light emitting diode display including both the color filter layer and the black matrix.

The present invention can provide an organic light emitting display device capable of improving process efficiency and improving contrast.

The present invention provides a substrate, a display portion formed on the substrate and having an organic light emitting element, an encapsulation layer formed on the display portion to encapsulate the display portion, a color filter layer formed on the encapsulation layer, and a protection formed on the color filter layer. An organic light emitting display device comprising a layer and a black matrix formed on the protective layer is disclosed.

In the present invention, the protective layer may be formed to cover the color filter layer.

In the present invention, the protective layer may contain an inorganic substance.

In the present invention, the protective layer may include any one selected from the group consisting of calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, and aluminum nitride.

In the present invention may further include a cover layer formed on the black matrix.

In the present invention, the cover layer may be formed to cover the black matrix and the protective layer.

In the present invention, the cover layer may contain an inorganic material.

In the present invention, the cover layer may include any one selected from the group consisting of calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, and aluminum nitride.

The organic light emitting diode display according to the present invention has improved process efficiency and improved contrast.

Hereinafter, with reference to the embodiments of the present invention shown in the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 is a schematic cross-sectional view of an organic light emitting diode display according to an exemplary embodiment, and FIG. 2 is an enlarged view of portion A of FIG. 1. In detail, FIGS. 1 and 2 illustrate an organic light emitting display device 100 of a passive matrix (PM) type.

The OLED display 100 includes a substrate 101, a display unit 120, an encapsulation layer 130, a color filter layer 140, a protective layer 150, a black matrix 160, and a cover layer 170. .

The substrate 101 may be made of a transparent glass material mainly containing SiO ₂ . The substrate 101 is not necessarily limited thereto, and may be formed of a transparent plastic material. When the substrate 101 is formed of plastic material, the substrate 101 may be made of polyethersulphone (PES), polyacrylate (PAR, polyacrylate), polyether imide (PEI, polyetherimide), polyethylene naphthalate (PEN, polyethyelenen). napthalate, polyethylene terephthalate (PET, polyethyeleneterepthalate), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose It may include an organic material selected from the group consisting of cellulose acetate propionate (CAP).

When the image is a bottom emission type organic light emitting diode display that is implemented in the direction of the substrate 101, the substrate 101 should be formed of a transparent material. However, when the image is a top emission type organic light emitting display device which is implemented in a direction opposite to the substrate 101, the substrate 101 may not necessarily be formed of a transparent material. In this case, the substrate 101 may be formed of metal. When the substrate 101 is formed of metal, the substrate 101 may include at least one selected from the group consisting of carbon, iron, chromium, manganese, nickel, titanium, molybdenum, stainless steel (SUS), Invar alloy, Inconel alloy, and Kovar alloy. It may include, but is not limited thereto. In addition, the substrate 101 may be formed of a metal foil.

The display unit 120 is formed on the substrate 101. The display unit 120 includes an organic light emitting element 125 that implements an image. FIG. 2 shows the display unit 120 in detail as an enlarged view of A of FIG. 1. The display unit 120 includes an organic light emitting element 125, and the organic light emitting element 125 includes a first electrode 121, an intermediate layer 122, and a second electrode 123.

The first electrode 121, which is an anode electrode, is formed on the substrate 101. The first electrode 121 is formed in a predetermined pattern by a photolithography method or the like. The first electrode 121 may be formed as a transparent electrode or a reflective electrode. When the first electrode 121 is formed of a transparent electrode, it may be formed of ITO, IZO, ZnO, or In ₂ O _3, and when formed of a reflective electrode, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd after forming the reflective film as Ir, Cr, and combinations thereof, etc., it can be formed by forming a film with ITO, IZO, ZnO or in ₂ O ₃ thereon.

The foregoing is an example in which the first electrode 121 is an anode electrode, but the first electrode 121 may be a cathode electrode. When the first electrode 121 is a cathode, the first electrode 121 may be formed of a metal material having a low work function such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, and a compound thereof. Can be.

The intermediate layer 122 is formed on the first electrode 121. The intermediate layer 122 includes an organic light emitting layer. The intermediate layer 122 includes a first intermediate layer 122a, a second intermediate layer 122b, and a third intermediate layer 122c. The first, second, and third intermediate layers 122a, 122b, and 122c may each include an organic light emitting layer that emits visible light of the same color. For example, the intermediate layer 122 may be an organic emission layer emitting white or blue visible light.

However, the present invention is not limited thereto. That is, the first, second, and third intermediate layers 122a, 122b, and 122c may include organic light emitting layers emitting various colors so as to correspond to the color filter layers 140, which will be described later.

The intermediate layer 122 may be formed of various organic materials. When the organic light emitting layer of the intermediate layer 122 is formed of a low molecular organic material, the intermediate layer 122 is a hole transport layer (HTL) and a hole injection layer in the direction of the first electrode 121 with respect to the organic light emitting layer. : HIL) and the like, and are formed such that an electron transport layer (ETL), an electron injection layer (EIL), and the like are stacked in the direction of the second electrode 123. In addition, the intermediate layer 122 may include various layers as necessary. Organic materials usable for forming the interlayer 122 are also copper phthalocyanine (CuPc), N, N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'- Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq3) and the like can be variously applied.

On the other hand, when the organic light emitting layer of the intermediate layer 122 is formed of a polymer organic material, it may include only a hole transport layer (HTL) in the direction of the first electrode 121 around the organic light emitting layer. The polymer hole transport layer may be made of polyethylene dihydroxythiophene (PEDOT: poly- (2,4) -ethylene-dihydroxy thiophene) or polyaniline (PANI) using inkjet printing or spin coating. It is formed on the electrode 121, the polymer organic light emitting layer may be used PPV, Soluble PPV's, Cyano-PPV, polyfluorene (Polyfluorene), etc. The color pattern can be formed.

The second electrode 123 is formed on the intermediate layer 122, and is formed in a direction crossing the first electrode 121. The second electrode 123 may be formed as a transparent electrode or a reflective electrode. When the second electrode 123 is formed as a transparent electrode, Li, Ca, LiF / Ca, LiF / Al, Al, Mg, and compounds thereof may be formed. After the deposition is directed toward the intermediate layer, the second electrode 123 may be formed by forming an auxiliary electrode or a bus electrode line thereon with a transparent conductive material such as ITO, IZO, ZnO, or In ₂ O ₃ . When the second electrode 123 is a reflective electrode, it may be formed by depositing Li, Ca, LiF / Ca, LiF / Al, Al, Mg, and compounds thereof. The above is the case where the second electrode 123 is a cathode electrode.

When the second electrode 123 is an anode electrode, the second electrode 123 is formed of a transparent conductive material having a high work function such as ITO, IZO, ZnO, or In 2 O 3.

When voltage is applied to the first electrode 121 and the second electrode 123 of the organic light emitting diode 125, visible light is emitted from the organic light emitting layer of the intermediate layer 122.

An encapsulation layer 130 is formed on the second electrode 123. The encapsulation layer 130 is to protect the organic light emitting device 125 from oxygen or moisture from the outside, and may have an organic, inorganic, or overlapping structure with an organic material.

In this case, since the encapsulation layer 130 is formed by stacking an organic material or an inorganic material, the encapsulation layer 130 of the thin film may be implemented. Preferably, the encapsulation layer 130 is formed to be 0.3 μm or less, thereby easily manufacturing the organic light emitting diode display 100.

Inorganic materials for forming the encapsulation layer 130 are various. Specifically, the encapsulation layer 130 includes calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, or aluminum nitride. can do. These inorganic materials prevent external moisture or oxygen from penetrating into the organic light emitting device 125.

In addition, the organic material for forming the encapsulation layer 130 includes various materials. As a specific example, the organic material for forming the encapsulation layer 130 includes a photo acrylic organic material or SiOC. Since the organic material may cover the fine particles, the encapsulation layer 130 having a flat surface may be easily formed.

The encapsulation layer 130 may be a single layer of an organic material, a single layer of an inorganic material, a plurality of layers of an organic material, a plurality of layers of an inorganic material, or an organic / inorganic stack.

The color filter layer 140 is formed on the encapsulation layer 130. The color filter layer 140 includes a first color filter layer 140a, a second color filter layer 140b, and a third color filter layer 140c. The color filter layer 140 is formed to correspond to the lower first electrode 121.

The first color filter layer 140a, the second color filter layer 140b, and the third color filter layer 140c implement different colors. For example, the first color filter layer 140a may be a red color filter layer or a second color. The filter layer 140b may be a green color filter layer, and the third color filter layer 140c may be a blue color filter layer.

The color filter layer 140 may be formed in various ways. Specifically, using the laser thermal transfer method, it is easy to form the color filter layer 140 without affecting the encapsulation layer 130 and the organic light emitting element 125 under the color filter layer 140.

The protective layer 150 is formed on the color filter layer 140 to cover the color filter layer 140. The protective layer 150 preferably includes an inorganic material. Specifically, the protective layer 150 includes calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, or aluminum nitride.

The black matrix 160 is formed on the protective layer 150. The black matrix 160 is formed in a predetermined pattern to correspond to the non-light emitting portion of the organic light emitting element 125. The black matrix 160 absorbs visible light incident from the outside and prevents color mixing and interference of visible light emitted through the color filter 140 to improve contrast of the organic light emitting diode display 100.

The black matrix 160 is formed by applying a black material to have a predetermined pattern and then performing a process such as a photolithography method. At this time, the lower color filter layer 140 may be damaged. In particular, when the black matrix 160 and the color filter layer 140 adhere to each other, the color filter layer 140 may be damaged or the patterning of the black matrix 160 may be incomplete during the patterning process of the black matrix 160.

However, in the organic light emitting diode display 100 according to the present exemplary embodiment, a protective layer 150 is interposed between the color filter layer 140 and the black matrix 160. The passivation layer 150 covers the color filter layer 140 so that the color filter layer 140 and the black matrix 160 are spaced apart from each other. Through this, the color filter layer 140 may be prevented from being damaged during the process of patterning the black matrix 160. In addition, the black matrix 160 is prevented from adhering to the color filter layer 140, so that the patterning property of the black matrix 160 is improved.

In particular, when the protective layer 150 contains an inorganic material, the protective layer 150 does not react with the developer when the development process is performed during the patterning process of the black matrix 140. Since it is not damaged and the adhesion between the protective layer 150 and the black matrix 140 is not large, patterning of the black matrix 140 is also facilitated.

Then, the cover layer 170 may be formed on the black matrix 160. The cover layer 170 covers the black matrix 160 and the protective layer 150 and contacts the substrate 101. In particular, the cover layer 170 may be formed larger than the encapsulation layer 130, and preferably, the cover layer 170 may be formed to correspond to the edge region of the substrate 101. Through this, the black matrix 160 and the color filter layer 140 may be protected from the outside.

The cover layer 170 includes an inorganic material. Specifically, the cover layer 170 includes calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, or aluminum nitride.

FIG. 3 is a schematic cross-sectional view of an organic light emitting diode display according to another exemplary embodiment. FIG. 4 is an enlarged view of B of FIG. 3. Specifically, FIGS. 3 and 4 illustrate an organic light emitting display device 200 of an active matrix (AM) type.

3 and 4, a thin film transistor TFT and an organic light emitting diode 225 connected thereto are illustrated on the substrate 201. The thin film transistor TFT includes an active layer 203, a gate electrode 205, a source electrode 207, a drain electrode 208, and the like. This will be described in detail.

A buffer layer 202 is formed on the upper surface of the substrate 201 to smooth the upper portion of the substrate 201 and to prevent impurities from penetrating into the substrate 201. The buffer layer 202 may be formed of SiO ₂ and / or SiNx.

An active layer 203 having a predetermined pattern is formed on the buffer layer 201. The active layer 203 may be formed of an inorganic semiconductor or an organic semiconductor such as amorphous silicon or polysilicon and includes a source region, a drain region, and a channel region.

A gate insulating film 204 is formed on the active layer 203, and the gate insulating film 204 may be formed of an inorganic material such as a metal oxide or a metal nitride, or an organic material such as an insulating polymer. In addition, the gate insulating layer 204 may be formed of SiO ₂ , SiNx, or the like.

The gate electrode 205 is formed in a predetermined region on the gate insulating film 204. The gate electrode 205 is connected to a gate line (not shown) for applying a TFT on / off signal. The gate electrode 205 may be made of a metal or an alloy of a metal such as Au, Ag, Cu, Ni, Pt, Pd, Al, Mo, or Al: Nd, Mo: W alloy, but is not limited thereto.

An interlayer insulating layer 206 is formed on the gate electrode 205, and the source electrode 207 and the drain electrode 208 are formed to contact the source and drain regions of the active layer 203 through contact holes. The TFT thus formed covers and protects the insulating film 209.

The insulating film 209 may be formed using an inorganic material and / or an organic material. As the inorganic material, SiO ₂ , SiNx, SiON, Al ₂ O ₃ , TiO ₂ , Ta ₂ O ₅ , HfO ₂ , ZrO ₂ , BST, PZT, etc. The organic material may include general general polymers (PMMA, PS), polymer derivatives having a phenol group, acrylic polymers, imide polymers, arylether polymers, amide polymers, fluorine polymers, p-xylene polymers, Vinyl alcohol-based polymers and blends thereof may be included. The insulating film 209 can also be formed from a composite laminate of an inorganic insulating film and an organic insulating film.

The first electrode 221 serving as the anode electrode of the organic light emitting element 225 is formed on the insulating layer 209. The first electrode 221 is formed to correspond to each pixel by the photolithography method.

A pixel define layer 210 is formed of an insulator to cover the first electrode 221. After a predetermined opening is formed in the pixel defining layer 210, an intermediate layer 222 is formed in a region defined by the opening.

The intermediate layer 222 includes an organic light emitting layer. The intermediate layer 222 includes a first intermediate layer 222a, a second intermediate layer 222b, and a third intermediate layer 222c. The first, second, and third intermediate layers 222a, 222b, and 222c may each include an organic light emitting layer that emits the same visible light. For example, the intermediate layer 122 may be a white or blue organic light emitting layer.

 However, the present invention is not limited thereto. That is, the first, second, and third intermediate layers 222a, 222b, and 222c may include organic light emitting layers that emit various colors so as to correspond to the color filter layers 240, which will be described later.

The second electrode 223 serving as the cathode of the organic light emitting element 225 is formed to cover all the pixels. Of course, the polarities of the first electrode 221 and the second electrode 223 may be reversed.

Since the materials for forming the first electrode 221 and the second electrode 223 are the same as the above-described embodiment, description thereof will be omitted.

The encapsulation layer 230 is formed on the second electrode 223. The encapsulation layer 230 is to protect the organic light emitting element 225 from external oxygen or moisture, and may have an organic, inorganic, or overlapping structure with an organic material.

There are various inorganic materials for forming the encapsulation layer 230. Specifically, the encapsulation layer 230 includes calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, or aluminum nitride. can do.

In addition, the organic material for forming the encapsulation layer 230 includes various materials. As a specific example, the organic material for forming the encapsulation layer 230 includes a photo acrylic organic material or SiOC.

The encapsulation layer 230 may be a single layer of an organic material, a single layer of an inorganic material, a plurality of layers of an organic material, a plurality of layers of an inorganic material, or an organic / inorganic stack.

The color filter layer 240 is formed on the encapsulation layer 230. The color filter layer 240 includes a first color filter layer 240a, a second color filter layer 240b, and a third color filter layer 240c. The color filter layer 240 is formed to correspond to the lower first electrode 221.

The first color filter layer 240a, the second color filter layer 240b, and the third color filter layer 240c implement different colors. For example, the first color filter layer 240a may be a red color filter layer or a second color. The filter layer 240b may be a green color filter layer, and the third color filter layer 240c may be a blue color filter layer.

The color filter layer 240 may be formed in various ways. For example, the color filter layer 240 may be patterned using a photolithography method.

The protective layer 250 is formed on the color filter layer 240 to cover the color filter layer 240. The protective layer 250 includes an inorganic material. Specifically, the protective layer 250 includes calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, or aluminum nitride.

The black matrix 260 is formed on the protective layer 250. The black matrix 260 is formed in a predetermined pattern to correspond to the non-light emitting portion of the organic light emitting element 225. The black matrix 260 absorbs visible light incident from the outside and prevents color mixing and interference of visible light emitted through the color filter 240, thereby improving contrast of the organic light emitting diode display 200.

The black matrix 260 is formed by applying a black material to have a predetermined pattern and then performing a process such as a photolithography method. At this time, the lower color filter layer 240 may be damaged. In particular, when the black matrix 260 and the color filter layer 240 are adhered to each other, the color filter layer 240 may be damaged or the patterning of the black matrix 260 may be incomplete during the patterning process of the black matrix 260.

However, in the organic light emitting diode display 200 according to the present exemplary embodiment, a protective layer 250 is interposed between the color filter layer 240 and the black matrix 260. The protective layer 250 covers the color filter layer 240 so that the color filter layer 240 and the black matrix 260 are spaced apart from each other. As a result, the color filter layer 240 may be prevented from being damaged during the process of patterning the black matrix 260. In addition, since the black matrix 260 is prevented from adhering to the color filter layer 240, the patterning characteristic of the black matrix 260 is improved.

In particular, since the protective layer 250 contains an inorganic material, the protective layer 250 is not damaged when the black matrix 240 is patterned, and the black matrix 240 is easily patterned.

The cover layer 270 is formed on the black matrix 260. The cover layer 270 is formed to cover the black matrix 260 and the protective layer 250. The cover layer 270 may be formed to have the same size as the encapsulation layer 230 or larger than the encapsulation layer 230. The cover layer 270 may protect the black matrix 260 and the color filter layer 240 from the outside.

The cover layer 270 includes an inorganic material. Specifically, the cover layer 270 includes calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, or aluminum nitride.

As described above, only the active organic light emitting display 200 having the top gate structure has been described. However, the present invention is not limited thereto and may be applied to various types of organic light emitting display. In particular, the present invention can be usefully applied to a flexible structure having a flexibility, a bendable display, and an ultra-thin structure.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a schematic cross-sectional view of an organic light emitting diode display according to an exemplary embodiment of the present invention.

FIG. 2 is an enlarged view of A of FIG. 1.

3 is a schematic cross-sectional view of an organic light emitting diode display according to another exemplary embodiment of the present invention.

4 is an enlarged view of B of FIG. 3.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

101, 201: substrate 120, 220: display unit

130, 230: sealing layer 140, 240: color filter layer

150, 250: protective layer 160, 260: black matrix

170 and 270: cover layers 100 and 200: organic light emitting display devices

Claims (8)

Board; A display unit formed on the substrate and including an organic light emitting element; An encapsulation layer formed on the display unit to encapsulate the display unit; A color filter layer formed on the encapsulation layer; A protective layer formed on the color filter layer; And An organic light emitting display device comprising a black matrix formed on the protective layer. According to claim 1, The passivation layer is formed to cover the color filter layer. According to claim 1, The protective layer includes an organic light emitting display device. According to claim 1, The protective layer includes any one selected from the group consisting of calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, and aluminum nitride. According to claim 1, And a cover layer formed on the black matrix. 6. The method of claim 5, The cover layer is formed to cover the black matrix and the protective layer. 6. The method of claim 5, The cover layer includes an inorganic material. 6. The method of claim 5, The cover layer includes any one selected from the group consisting of calcium oxide, alumina, silica, titania, indium oxide, tin oxide, silicon oxide, silicon nitride, and aluminum nitride.

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